package leetcode;

import java.util.Stack;

public class LeetCode20 {


    public boolean check(String s){
        Stack<Character> stack = new Stack<>();
        for (int i = 0; i < s.length(); i++) {
            char c = s.charAt(i);
            if (c == '(' || c == '['|| c == '{'){
                stack.push(c);
            }else {
                if (stack.isEmpty()){
                    return false;
                }
                Character peek = stack.pop();
                if (c==')' && peek != '(')
                    return false;
                if (c==']' && peek != '[')
                    return false;
                if (c=='}' && peek != '{')
                    return false;
            }
        }
        return stack.isEmpty();
    }

}
